Variable energy accelerator incorporating an electronic rangefinder

Abstract

A system which adjusts the muzzle energy of an adjustable velocity accelerator in response to signals from a connected rangefinder or imaging device. Embodiments of the invention may be used to enhance the safety of a less-lethal weapon system by automatically adjusting its muzzle energy to compensate for a target moving closer or further away, or preventing injury to an unintended third party who crosses into the line of fire at close range. The preferred embodiment relates to a portion of an active control system for a coilgun or railgun. Other embodiments may be applicable to precision targeting for defense / military applications, or integrating an identification friend-or-foe (IFF) system in combination with a rangefinder to reduce the risk of friendly fire incidents.

Description

Variable Energy Accelerator Incorporating an Electronic RangefinderCROSS-REFERENCE TO RELATED APPLICATIONThis application claims benefit of priority to U.S. provisional patent application serial number 63 / 555,494 filed 20 February 2024., under 35 U.S.C. §119(e), which are incorporated by reference herein in their entirety.TECHNICAL FIELDThis invention relates to a method of automatically adjusting the muzzle energy of a “smart” weapon system based on desired energy on target, range to target, and / or an identification friend-or-foe (IFF) signal.BACKGROUND

[0001] In the current state of the art, projectile-based small arms can largely be classified as one of two types: lethal and less-lethal. The use-case for each is distinct, and the mechanism of operation is generally distinct as well.

[0002] Lethal small arms primarily consist of firearms, with some high-end air rifles and specialized electromagnetic accelerators also falling into the category.

[0003] Less-lethal weapons is a far broader category, encompassing a small number of power-based devices (such as flash-bangs and rubber bullets), as well as a broad field of air, spring, electronic, electro-magnetic, light, sound, and chemical agents.

[0004] However, outside of the above broad categories, pinning down what constitutes a lethal vs. a less-lethal weapon is both a scientifically and legally complex question.

[0005] Many countries, states, and cities place far greater restrictions on what they consider a lethal weapon vs. a “non-lethal” weapon. These thresholds are often arbitrary and non-scientific.

[0006] For instance, Chinese authorities define a lethal weapon as any projectile with over 1.8 Joules (J) per square centimeter (cm2) muzzle energy to cross sectional area ratio, neglecting air friction and ballistics. This places nearly all projectile devices (including toy airsoft guns and some baseball pitchers) in the category of “lethal weapons”.

[0007] Germany and Hungary set their threshold purely on the basis of muzzle energy; any device capable of delivering a projectile with over 7.5 J muzzle energy is considered a “firearm” and therefore a lethal weapon. In Sweden, this threshold is 10 J. The United Kingdom: 16 J. Poland: 17 J. Slovenia: 20 J or 200 m / s (whichever is greater). Russia: 25 J. Other countries have muzzle length restrictions, or other complex tiered permitting systems imposing incrementally stricter restrictions depending on combinations of muzzle energy, velocity, or other factors.

[0008] A commonly cited metric for determining projectile energy is the “Taylor Knock-Out Factor” (TKOF), which is calculated by multiplying a projectile’s momentum by the diameter of the projectile, divided by a constant (3505.55 for SI units). However, it may also be argued that such a definition does notrepresent an accurate measurement of the lethality of a projectile, as a larger object (like a baseball) traveling at the same speed as a smaller object (like a lead ball) would have a higher TKOF, despite a lower risk of injury. Rather, such a metric may correspond to the effectiveness at stopping or deterring an attacker.

[0009] Perhaps the most credible examination of this subject was conducted by the FBI, in their 1989 report on handgun wounding factors and effectiveness. They conducted a scientific study and defined that lethality could only be assessed in terms of bullet penetration, rather than muzzle energy- classifying 7-12” of ballistics gel penetration as a lethal weapon.

[0010] Cyrille Raquin (et al.) in W02009141521A1 teaches that “the effective limit of non-lethality is close to 30 J”.

[0011] However, a bb-gun (with a muzzle energy of 1-5 J, or 3.3-16 J / cm2) is also potentially lethal in certain circumstances because its muzzle velocity is greater than 60 m / s and therefore is capable of fracturing bone.

[0012] Rubber bullets, such as those commonly used in law enforcement applications are typically fired from a shotgun barrel with a mass approximately 140g (in the case of slugs) or 3-5g (in the case of rubber buckshot). They are designed to be fired at ranges no less than 30-70m. Such “less-lethal” rounds are designed to provide a less-lethal deterrent at relatively long range in order to prevent would-be attackers from getting within striking distance of law enforcement. Such weapons typically have a muzzle velocity of 60-80 m / s and muzzle energy of 300-400 J. However, despite their classification as “less-lethal”, when fired at close range (at targets under 30m), such devices can (and commonlydo) cause serious and potentially fatal injuries. There is no velocity adjustment setting possible for such weapons, and as a result they are frequently involved in fatal injuries, often in situations where law enforcement have no intention of using lethal force.

[0013] For a system to be definitively less-than-1 ethal, its energy on target should be less than 30 J, its energy to area ratio less than 3 J / cm2. Furthermore, what may be less-lethal at long range may be lethal at close range, an ideal less-than-lethal weapon should be able to very its muzzle energy in order to a deliver constant energy on target regardless of range, and its velocity on target should be no greater than 60 m / s.

[0014] Sandia National Laboratories in their 2003 project to create a less-lethal ballistic launcher integrating a rangefinder took on this endeavor, ultimately creating a system capable of delivering a foam-tipped 75g, 40mm projectile to a distance between 20- 100m with an initial velocity of 61 m / s and a goal of achieving a “lower probability of inflicting harm to the target”. Such a projectile would have a muzzle energy of 140 J or a TKOF of 52.2. However, their projectile was foam-tipped to reduce impact force, and their study also involved the use of energetic (flash-bang) devices.

[0015] In light of the above, constructing a system to be less-than-lethal at all ranges has presented a considerable challenge to the defense industry. This is because most projectile weapons operate by having a fixed projectile and a fixed means for delivering an amount of energy to said projectile.

[0016] Despite the challenges involved, some in the prior art have succeeded at developing systems able to dynamically adjust either the energy delivered to a projectile, or a projectile’s mass in response to changes in range or actions by a user. Still other systems in the prior art have attempted to integrate rangecorrection into a computer-aided targeting subsystem of a projectile weapon. Yet others have attempted to prevent friendly-fire incidents by integrating an identification friend-or-foe (IFF) means into a computer-controlled fire control mechanism of a projectile weapon.

[0017] Perhaps the most similar systems in terms of overall intended functionality in the prior art are that of US Pat. 9,222,737 and 8,322,329.

[0018] The ‘737 patent teaches towards an adjustable-velocity gun operated by combustible propellant, which is able to deliver both lethal or non-lethal projectile energy and may integrate an automatic range finding device to vary the propellant levels in order to achieve a desired velocity at a given distance. They teach that such a system may operate between 45-85 m / s and may operate at a range between 5-100m. The ‘737 patent primarily focuses on a system that varies the amount of propellant injected into a combustion chamber which determines the amount of energy delivered to the projectile. Such a system is relatively high in complexity as it must integrate combustion, electrical, mechanical, and computerized systems- all with many moving parts and risk of failure on any one of which could precipitate a catastrophic explosive failure with potentially lethal consequences for the operator. Furthermore, such a system necessitates the storage of a significant quantity of high pressure fuel and oxidizer gases on aportable weapon system, which may not be ideal for some law enforcement situations.

[0019] The ‘329 patent teaches a computer-integrated air gun with a muzzle energy which is varied by controlling the amount of air pressure used to accelerate a projectile. The amount of air pressure used is controlled through the action of effectively a solenoid value that is opened for a variable amount of time. They teach such a system could deliver a muzzle energy as low as 4 J or as high as 3260 J. Such a system may also incorporate a feedback loop to effect more accurate control over the pressure delivered to a firing chamber. The system of the ‘329 patent is considerably simpler that that of the ‘737 patent in that it relies solely on a single electropneumatic component (a high-pressure solenoid valve), and minimal other electronic or mechanical components. It also has much greater safety than combustion-based systems since the highest pressure ever experienced within the device that which is already contained in the air tank. However, the ‘329 patent does not teach towards a non-1 ethal or variable lethality implementation of the weapon, nor does it mention the use of rangefinders or other distance sensors to determine the appropriate amount of muzzle energy to deliver a specified energy on target.

[0020] It is known to those of ordinary skill in the state of the art that electromagnetic accelerators, which comprise reluctance coilguns, inductance coilguns, Thompson launchers, reconnection guns, railguns, etc. are purely electronic systems with few or no moving parts. Such systems are imminently capable of varying their muzzle energy (via timing, coil sequencing, voltage, orother methods) based on user input and can achieve both potentially lethal and non-lethal muzzle energies. However, until very recently, such systems have been low in technical maturity and man-portable embodiments of these devices have not been available.

[0021] Electromagnetic accelerators can accelerate ferromagnetic projectile payloads or non-ferromagnetic projectile payloads. Coilguns specifically can accelerate such payloads with no contact between the projectile and the barrel, and with no moving parts, allowing for a wide selection of ammunition types to be fired from such weapons- including less-lethal foam tipped, rubber-coated or rubberized magnetic projectiles.

[0022] Electronic rangefinders have been available since the late 20thcentury, but portable implementations specifically with ranges and accuracies useful for ballistic trajectory determinations have been limited to military applications until the early 21stcentury due to high cost. Recently, such devices have which operate based on time of flight (ToF) laser or Lidar mechanisms have become available for a variety of applications due to widespread commercial sales of low-cost miniaturized systems such as the Benewake TFMini and TFMini-Plus distance sensors which deliver reliable and accurate laser distance measurements of ranges up to 12m. Other distance sensors widely available on the commercial market include the Garmin Lidar Lite and Lidar Lite HP which can sense targets at a distance of up to 40m in a low-cost miniaturized form factor. Still other, longer range sensors are available however their cost and complexity is greatly higher than the shorter range sensors mentioned above.

[0023] IFF systems typically involve a transponder that listens for an interrogation signal and sends a response. Such systems can be implemented using optical, sound, RF or other means of signal transmission and response. Such systems are typically not integrated directly into small arms intended for use in a lethal / defense capacity as the added complexity and chance for misidentification in a life-or-death situation presents a higher than acceptable risk for many operators. However, in the context of a less-than-lethal system where the objective is to deter and repel, rather than to defeat, injure or kill- such IFF controls may be greatly advantageous in preventing friendly-fire situations, as typically law enforcement has several less-than-lethal tools at their disposal should one system fail in its task of IFF identification.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 depicts a flow chart of the operation of an embodiment of the present invention, where the boxes with dashed borders represent optional components of the embodiment.

[0025] Figure 2 depicts one embodiment of a variable lethality projectile for an electromagnetic accelerator-based embodiment of the present invention.

[0026] Figure 3 depicts various user-selectable mode settings of an embodiment of the invention.

[0027] Figure 4 depicts a representative scenario where the present invention is used in a less-lethal configuration, pointed at a distant target and configured to deliver a projectile with less-than-lethal impact effects.

[0028] Figure 5 depicts the scenario of Figure 4 wherein a secondary target transits between an operator of the present invention and an intended target with the weapon configured to deliver less-than-lethal impact effects.

[0029] Figure 6 depicts a scenario where a lethal threat is posed by secondary target, and an operator of the present invention selects an operating mode intended to deliver maximum (potentially lethal) force.

[0030] Figure 7 depicts a scenario where a unit possessing a means for IFF transits between an operator and a target, and the weapon displays a warning to an operator, preventing them from firing the weapon accidentally in the direction of a potentially friendly unit.DETAILED DESCRIPTION

[0031] In an embodiment, the invention is a system for automatically adjusting the muzzle energy of a weapon (98) to achieve a desired effect on target.

[0032] In one embodiment, the invention is a system which comprises an adjustable energy weapon (98), such as a coilgun, railgun, quench gun, air rifle, spring gun, bb-gun, combustion-based propellant gun, firearm, or other method for expelling a projectile with a variable energy known to those of ordinary skill.

[0033] In an embodiment, a prototypical system of operation is depicted byFigure 1, wherein an operator pulls a trigger (99) connected to the weapon (98), to which is attached a microcontroller (100) which may be a microprocessor or an information processing system comprising a memory, a processing unit, inputs, outputs, sensors, RAM, ROM, power supply, and other necessary components which may be surmounted or placed upon or connected to printed circuit boards which may be hardened or potted in polymer or rubber to guard against heat, cold, moisture, shock, vibration, recoil, vacuum or other harsh conditions.

[0034] In an embodiment, the microcontroller (100) is an Atmel 32u4, Atmel ATmega328, ATmega2560, ST Electronics STM32, ESP32, ARM Cortex-M series, or another Texas Instruments, Atmel AVR-series, or other Reduced Instruction Set (RISC), x86, ARM or other type integrated microcontroller / processing unit. In an embodiment, the microcontroller (100) is a system on a chip (SoC). In an embodiment, the microcontroller (100) operates on 5V logic. In an alternate embodiment, the microcontroller (100) operates on 3V3 logic. In still alternate embodiments, the microcontroller (100) may operate on any other preset logic threshold voltage or the microcontroller may be analog in nature. In embodiments of the invention relating to electromagnetic accelerators it is preferrable for the microcontroller to have a higher logic voltage (5V) as this generally results in fewer processing errors due to electromagnetic interference during the weapon’s firing. In embodiments relating to certain induction coilguns, high energy reluctance coilguns, field-augmented, actively-switched, plasma armature or armature-switched railguns, additional protective circuit elements(such as transient voltage suppression diodes, metal oxide varistors, zener diodes, snubber capacitors, crowbar circuits, active or passive filters, etc.) may be required to be placed physically or electrically close to the microcontroller (100) as the discharge of such weapons produce broad-spectrum electromagnetic interference (EMI). In an embodiment, the microcontroller (100) is integrated onto a prebuilt microcontroller board platform such as the Arduino, or Raspberry Pi. In an embodiment, the microcontroller (100) is an Arduino Nano or Arduino ProMega which has been potted in silicone elastomer, polyurethane elastomer, epoxy resin, or other protective chemical compound. In an embodiment, the reset pin of the microcontroller has been electrically isolated by means of passive or active fdters, snubber capacitors, jumpers, or other methods known to those of ordinary skill for preventing inadvertent activation due to EMI.

[0035] In an embodiment, the microcontroller (100) possesses a memory with some initial state at some time when the trigger is pulled (99). Said microcontroller (100) may continuously interrogate or receive various sensors and inputs prior to the trigger pull (99) or it may interrogate or receive sensor readings immediately upon sensing the trigger pull (99).

[0036] In an embodiment, the systems attached to the microcontroller by some or multiple independent or redundant means may comprise: a sensor for determining the stored energy within a reservoir of the weapon (102), a rangefinder (104), temperature sensors (106), a user-interactive mode selector switch (108), a user- interactive safety switch (110), an IFF override button or switch (111), a tiltsensor or accelerometer (112), as well as other sensors, inputs, or information receiving devices known to those of ordinary skill.

[0037] In embodiments of the invention, a “switch” or a “button” may refer to one of many different mechanical, electronic, electrical, magnetic, optical, optoelectronic, acoustic, RF, or other means for selecting a binary (on / off) functionality by a user or other remote system or individual, known to those of ordinary skill in the state of the art.

[0038] In an embodiment, the sensor for determining the stored energy within a reservoir (102) may be a voltage divider for sensing the voltage within a capacitor bank or battery, which may include an optocoupler or other means for communicating a high level of electrical energy to a microcontroller (100) with minimal risk of damage to sensitive components. In an embodiment, the sensor (102) may comprise a voltage to frequency converter. In an embodiment, the sensor (102) may be a pressure sensor for detecting the pressure within a gas reservoir. In an embodiment, the sensor (102) may be an encoder or other means for converting mechanical position to electrical signals. In an embodiment, the sensor (102) may be a force sensor or strain gauge or other means for measuring and transmitting the weight or volume of an energetic compound. In an embodiment, the sensor (102) may be a mass-flow sensor or other means for measuring and transmitting the mass or volume of an energetic or reactive gas, liquid or fluid into a reaction or combustion chamber. In alternate embodiments, the sensor (102) may be feedback from a screw, auger, solenoid valve, relay, transistor, vacuum tube, stepper motor, or other means for metering out a quantityof electrical, mechanical, pneumatic, explosive, combustible, or other form of energy from a storage vessel into a reservoir receiver.

[0039] In an embodiment, the rangefinder (104) may sense distances at a range between 0.2-1000 m. The effective range of the rangefinder (104) should roughly correspond to the effective range of the weapon system (98) to which it is attached. Rangefinder precision beyond ±0.1 m of range is generally not advantageous to the functionality of the invention. The rangefinder (104) may be ultrasonic, sonar, RF, microwave, millimeter wave, laser time of flight, LIDAR, optical camera, microbolometer, multi-pixel thermal imager, infrared, hyperspectral, pulsed laser, continuous wave laser, passive or active, triangulation based, or connected to a third party rangefinder system through communication links. In an embodiment, the rangefinder (104) may use near-infrared lasers or light emitting diodes (LED) to actively illuminate a target. In an embodiment, the rangefinder (104) may be an optoelectronic system which employs optical lenses to sense targets at a maximum range corresponding to the effective range of the weapon system (98). In an embodiment, the rangefinder (104) is a Benewake TFMini, or Benewake TFMini-Plus, or Garmin Lidar Lite or Lidar Lite HP commercial laser ToF package. Other, longer range rangefinders may be required for embodiments of the invention which relate to air guns, combustion-based propellant guns, railguns, or firearms.

[0040] In an embodiment, the invention may utilize temperature sensors (105) to analyze whether sub-systems of the weapon system (98) are safe to fire. Such temperature sensors (105) may be particularly advantageous to place upon thebarrel of a firearm or combustion-based weapon, or surmounted on a reaction chamber or combustion chamber of a combustion-based embodiment. Said sensors (105) may be advantageous to place on the drive coils, rails, or power supply, battery or other heat-generating or heat-sensitive portions of an energy weapon. Such sensors (105) may be type NTC or PTC thermistors, ceramic conduction-based temperature sensors, capacitive temperature sensors, PT 100 or PT1000 resistance thermometers, or thermocouples such as Type-J, Type-K, Type-M, precious metal, or other variants of Seebeck effect detectors known to those of ordinary skill in the state of the art.

[0041] In an embodiment, the invention may have a display (106) which shows values and / or pictorial or graphic depictions of various sensor readings which may comprise a selection of measurements and settings such as the energy stored (102), range to target as detected by the rangefinder (104), temperature of critical components from the temperature sensors (105), or a current desired energy setting (107), current mode setting (108), safety engagement status (110), IFF override status (111), or other current settings or measurements of sensors, inputs, or outputs connected to the microcontroller (100). The display may be surmounted physically to the weapon system (98) or the weapon system may remotely transmit and receive data from a distant station which contains a display, or a display may be omitted entirely in order to ruggedize the system or reduce the chances for enemy detection of the system. In embodiments where a display(106) is surmounted to the weapon system, it may be a visible, UV or infrared type LED-lit screen or matrix, or a vacuum-fluorescent display, or an organicLED display (OLED), or a liquid crystal display, or laser projection, or holographic, or one of many different display technologies known to those of ordinary skill. In an embodiment the display (106) is a commercially available low power SSD1306 visible OLED-type display.

[0042] In an embodiment, an operator of the invention may set a desired energy on target (107) which the microprocessor will execute a process in order to achieve. This setting may be digitally input using means such as up / down / select buttons using a display (106) for reference. In preferred embodiments of the invention, the setting may be as simple as turning an encoder wheel, rheostat or potentiometer from “low” to “high”. In other embodiments of the invention, the setting may be accomplished by means of depressing the trigger (99) with a varying pressure or to a varying distance or for a varying amount of time to communicate to the microprocessor (100) a desired energy setting to deliver (107). In other embodiments, the energy setting may be set remotely by means of an RF or other communication link with a superior officer or other designated individual or who is tasked with designating targets.

[0043] In an embodiment, an operator of the invention may select from various modes of operation (108) of the weapon system (98). Such modes may include: max power, min power, lethal, less-lethal, proportional, inverse-proportional, constant energy at range, “smart”, lethal within or beyond (X) feet (where X is a rangefinder distance), less-lethal within or beyond (Y) feet (where Y is a rangefinder distance), IFF active, IFF inactive, automatic, semi-automatic, burst, safe. In a preferred embodiment, modes (108) may include: full power, manualand “smart”, with the desired energy setting (107) determining either the muzzle energy (in the case of manual mode), or the desired energy on target (in “smart” mode). In such an embodiment, the manual mode would bypass the rangefinder and simply fire the weapon with a user-selected energy regardless of range to target. In such an embodiment, the full power mode would bypass all energy irrelevant computerized features and simply fire the weapon at maximum muzzle energy. Figure 3 depicts several embodiments of potential modes (108) and energy settings (107) in greater detail and is discussed below.

[0044] In an embodiment, the invention may also integrate a safety (110) switch, button, toggle, mechanical linkage, valve or other feature for ensuring the weapon (98) is not fired inadvertently.

[0045] In an embodiment, a switch, button, toggle, mechanical linkage, valve or other feature is used to override a positive IFF designation (111) by the microcontroller and / or IFF sensor(s). Such a device is intended to provide the user the ability to still fire the weapon (98) in the case of a false positive IFF designation, an incidence of hacking, EMI disruption, or other unforeseen circumstance where the IFF system does not perform its intended purpose.

[0046] In an embodiment, an accelerometer and / or tilt sensor (112) is connected to the microcontroller (100) for the purpose of analyzing recoil impulse (to determine a mass of the projectile). A tilt sensor may be used to detect the firing angle in order to determine the ballistic trajectory and subsequently the amount of air resistance a projectile is likely to encounter on its trajectory to target, which may then be compensated for by increasing or decreasing muzzle energy at thetime of firing. Said accelerometer may be 3-axis, 6-axis, 9-axis or any other variety of mechanical, gyroscopic, optical, MEMS, hall-effect or any other means for determining and sensing the rate of change of relative or absolute position of an object, known to those of ordinary skill in the state of the art. Said tilt sensor may be independent from, or one-and-the-same as said accelerometer.

[0047] In an embodiment, the trigger (99) along with the other systems (102) (104) (105) (107) (108) (110) (111) and (112) are electrically connected to the microcontroller (100) by means of wires and a microswitch. In an embodiment, the trigger contains a magnet where its movement is sensed by a hall-effect sensor, coil of wire, or other means of sensing the position of a magnet by a microcontroller (100). In other embodiments, the trigger is connected by means of a mechanical linkage, optical, acoustic, or other system for connecting a mechanical user input to an information system in a reliable and durable fashion.

[0048] Upon a trigger pull (99) sensed by the microcontroller (100), in an embodiment of the invention, said microcontroller compares the sensor and input values with safe ranges for said sensor and input values stored within a memory of the microcontroller, and determines (114) whether to proceed with the firing sequence. If the system would be unsafe, unable, or undesirable to fire for whatever reason, the system may output a visual, auditory or other warning message to the display (106) or other output means to the operator or a remote party and return to the start of the flow chart depicted in Figure 1. If the system is otherwise safe and able to fire, the microcontroller (100) proceeds with the firing sequence and takes a rangefinder and optionally an IFF sensor reading (115).Following such a reading, the microcontroller begins accelerating a projectile. In embodiments of the invention where various stages are present (such as embodiments drawn to multi-stage coilguns), the microcontroller may activate a single stage (116) to begin the firing sequence. In other embodiments drawn to combustion, air pressure, mechanical force or otherwise, the later computation steps may be accomplished prior to initiation of projectile acceleration, since the determination of muzzle energy is required prior to metering of the stored energy means to the projectile acceleration means (reaction chamber, combustion chamber, air valve, spring force, etc.) In an embodiment of the invention drawn to a railgun, calculations may need to be accomplished prior to conduction of energy through the rails, as in some types of railgun systems this discharge cannot be shut down once initiated by projectile conduction, thyristor activation, etc.

[0049] In an embodiment of the invention where stored energy is used for acceleration means and multiple acceleration stages are present, a timer (118) may be started after the first stage acceleration means is activated. While said timer is active, the microcontroller (100) may analyze the position of the projectile through RF, optical, acoustic, electrical, inductive, capacitive, or other sensing means known to those of ordinary skill. While said first acceleration stage (116) is actively accelerating the projectile and said timer (118) is active, the microcontroller may take accelerometer readings (122), if an accelerometer (112) is present, or merely wait (123) until the projectile reaches a given distance of travel or has left the first acceleration stage (120). When such event occurs, the microcontroller (100) may use this data to compute the mass of a projectile (124),given a known approximate weapon system mass (98), and velocity (from the distance, 120 covered in a unit of time 118) via conservation of momentum and other Newtonian equations of motion known to those of ordinary skill.

[0050] In alternate embodiments of the invention, a system (98) may be only configured to fire a fixed projectile mass and such calculations are not necessary. In other alternate embodiments of the invention, a projectile mass may be input by the user or stored in memory prior to firing, or by a remote third party or system via a communication means.

[0051] Either prior to, at the same time, or after this calculation (124) is takes place, the second stage of the firing sequence (126) begins. In embodiments of the invention relating to energy weapons, this may be the second electromagnetic accelerator stage, or second level of capacitor energy stored in a bank of capacitors, etc. Either prior to, at the same time, or after this acceleration stage fires (126), a calculation is done to compute the density of the projectile (128). This is necessary in order to determine the amount of air resistance which will need to be compensated for. Such a determination is not always necessary, but may be advantageous for improving the performance of certain embodiments of the invention. Such a density calculation may be difficult or even impossible to accomplish earlier in the firing sequence of embodiments of the invention which use inductive or optical sensing of the projectile as it is accelerated, as two points of measurement may be required to determine the length of a projectile in addition to its velocity. In embodiments of the invention where a RF or anothercontinuous projectile position sensing system are present, such a calculation can be performed earlier in the firing sequence.

[0052] Similar to (124), in alternate embodiments of the invention, a system (98) may be only configured to fire a fixed projectile length or density and such calculations are not necessary. In other alternate embodiments of the invention, a projectile length or density may be input by the user or stored in memory prior to firing, or by a remote third party or system via a communication means.

[0053] Once the microcontroller (100) has determined the projectile’s ballistic parameters, lookup tables or other analytic or numerical means (129) may be employed to calculate or determine the energy a projectile will carry to its target at a given distance (115) for a given muzzle energy. Then, the appropriate muzzle energy with which to fire the projectile to achieve a desired energy (107) on target can be determined.

[0054] Again, lookup tables or other analytic or numerical means (130) may be used to determine how many stages to activate or the voltage to charge or discharge from a capacitor, or the length of time to allow gas pressure through a solenoid valve into a barrel, or mass of energetic / combustible material to meter, or otherwise determine the amount of energy to deliver from the system (98) to a projectile to effect a certain muzzle energy (132).

[0055] Once the above firing sequence is complete, the system may return to its original state, or employ feedback / detection means to reduce error for subsequent shots, or perform other functions necessary as determined by the specific system type and application for which the system is being used.

[0056] Projectile means (133) for an embodiment of the present invention are depicted in Figure 2. In an embodiment of the projectile (133), a comparatively soft rubberized or foam coating (134) within which may be placed an optional polymer or metal foil burst disc (135), and said soft coating (134) may surround a harder inner core (136) of the projectile (133). In an alternate embodiment, the entire projectile means (133) may be made from a single either hard or soft uniform or composite material. In alternate embodiments, there may be more than one inner core (136) present within a slug of rubberized coating matrix (134). In other embodiments, a plurality of smaller soft-coated projectiles may be packed into a single firing unit (133) and fired at the same time or sequentially from the weapon system (98).

[0057] In an embodiment, a variable lethality projectile (133) may be constructed in such a way that when said projectile (133) strikes a target at a certain low energy, a burst disc (135) resists puncture by the inner core (136) and presents a comparatively softer impact surface, reducing projectile damage to target. In an embodiment, when said projectile (133) strikes a target at a higher energy, the burst disc (135) is punctured by the inner core (136) upon impact and strikes a target with a more pointed, potentially injurious projectile. In such embodiments, a mass-producible, passive projectile may be fired from the same weapon system (98) in both a lethal and less-lethal configuration.

[0058] In alternate embodiments, the burst disc (135) may be omitted due to the strength of the outer coating (134), or the disc (135) may take the form of a fiberous weave, or randomly dispersed fibers within the coating (134). In alternateembodiments, the projectile may take one of a variety of geometries discoverable without undue experimentation by those of ordinary skill in the art. In alternate embodiments, the disc (135) may be placed on the outer surface of the projectile rather than embedded within the coating (134). In still alternate embodiments, the disc (135), if present, may be present on one or a plurality of sides or surfaces of the coating (134) or the core (136).

[0059] In an embodiment, the core (136) may be made from hydrogen-annealed iron, mild steel, alloy steel, ferrite, iron filing epoxy, sendust, permalloy, hiperco, or one or several other alloy or iron, nickel or cobalt, or other ferromagnetic material(s). In an alternate embodiment, the core (136) may be made from copper, aluminum, calcium metal, silver, superconductor, or another highly electrically conductive material or alloy or combination of materials. In an embodiment, the coating (134) may contain ferromagnetic or conductive particles or may itself be ferromagnetic or conductive in nature. In an embodiment, the core (136) may be omitted and the entire projectile comprised of elastomeric shear thickening or other non-Newtonian material.

[0060] In an embodiment, the coating (134) may be made from latex, chloroprene, synthetic isoprene, butyl, nitrile, silicone, Viton, or one of many elastomeric or polymeric materials known to those of ordinary skill. In an alternate embodiment, the coating (134) may be made of non-Newtonian material. In an embodiment, the coating (134) may be made of a soft metal such as lead or indium. In alternate embodiments, the coating may be porous, open cell, or closed cell polymeric foam. In an embodiment, the coating may possess an outer layermade of a different material to facilitate lower friction during acceleration, a discarding sabot, or contain a chemical agent such as CS, CN, OC, CR, benzyl chloride, thioacetone, denotonium benzoate, or one of a number of non-lethal riotcontrol agents commonly or occasionally employed in similar applications.

[0061] In an embodiment, the disc (135), if included, is made from cotton, nylon, polypropylene, polyethylene or a per-fluorinated or per-chlorinated polymeric fiber, or cellulose-derived material. In an alternate embodiment, the disc (135), if included, is made from aluminum or stainless steel foil. In an embodiment, the disc (135), if included, may be comprised of any thin or fibrous or particulate material with a known impact, shear, or tensile strength known to those of ordinary skill.

[0062] In an embodiment, several discs (135) may be present with a chemical agent, or pigment dye, or intermediate hardness material present between the plurality of discs to effect a continuum of force applications from a single projectile. In such an embodiment, a low energy projectile may simply bounce off a target without inflicting damage. An intermediate energy projectile may burst the first of a plurality of such burst discs (135) releasing a mild odorous chemical agent or marking dye. A still higher energy projectile may burst a second disc, releasing an incapacitating agent such as CS or OC. Lastly, a high energy projectile may allow the core to penetrate the plurality of burst discs, delivering a potentially lethal wound. Such a projectile fired from a system of the present invention may present operators a continuum of force options from a single weapon system, allowing for the lowest necessary force to be used in order toachieve a desired outcome without the need to carry many different cumbersome systems- thereby increasing the odds that an operator may choose to use a less- lethal option and ultimately reduce harm to individuals.

[0063] In alternate embodiments of the invention pertaining to air guns, firearms, combustion weapons or other acceleration technologies, the core (136), coating (134), and disc (135) if included may be made from other metal, polymeric, ceramic, or composite materials suitable for such an acceleration type and known to those of ordinary skill in the art.

[0064] Figure 3 depicts an embodiment of a variety of different operating modes (108) and desired energy setting (107). (140) (142) and (144) depict mid, high, and low energy settings (107) respectively, in the manual operating mode (108). (146) (148) and (150) depict mid, high, and low energy settings (107) respectively, in the “smart” operating mode (108). In this embodiment, a “full power” mode would bypass all energy settings and default to the state depicted in (142). In Figure 3, the muzzle energy of the weapon (98) is depicted on the vertical axis of a display (106), and the rangefinder (104) reading is depicted on the horizontal axis corresponding to the vertical striped area under the curve. As the rangefinder (104) detects objects or targets at a range, the shaded area of the graph expands or contracts left or right, and the muzzle energy delivered responds according to the various schemes depicted by the Figure. In alternate embodiments, other schemes for determining, selecting or commanding different muzzle energy settings may be used and the schemes depicted by Figure 3 onlyrepresent on potential embodiment of a prototypical control and display scheme for the invention.

[0065] Figure 4 depicts a potential scenario where an embodiment of the present invention may be used. In this figure, a weapon system (98) possessing an energy storage means (102), a rangefinder (104), and a display (106) as well as the computerized components of the present invention is shown. Below is depicted a notional display state corresponding to the energy which the weapon (98) will impart to a projectile in order to deliver a mid-level energy on a target at a long range. In this scenario, a target is a hostile but not imminently threatening unit at a long range (158), shown as a circle with a horizontal bar. The system (98) will correspondingly fire at a high muzzle energy to deliver a less-lethal round to the target at long range. In this figure, a second hostile unit (160) and a friendly unit (162) are shown but are not directly in the system’s line of fire.

[0066] Figure 5 depicts a progression of the scenario shown in Figure 4, wherein the second hostile (160) unit (who is still un-armed or does not present an imminent threat) passes between the operator of the system (98) and their original intended target (158). The system (98), which is still configured to deliver a less- lethal energy, automatically reduces its muzzle energy in response to the rangefinder (104) sensing the now much closer target position of (160). If a weapon system did not possess an embodiment of the present invention, such a scenario could result in the unintentional injury of the second target (160).

[0067] Figure 6 depicts an alternate potential progression of the scenarios depicted in the earlier figures, wherein the closer figure (164) now presents alethal threat to the operator. In such a scenario, the operator may quickly switch from the less-lethal “smart” mode to a “full power” mode of operation in order to counter the threat.

[0068] Figure 7 depicts an alternate scenario where an embodiment of the invention contains an IFF system and the friendly unit (162) contains an IFF transponder or other means for identifying itself as friendly. In such a scenario, the system (98) would block the operator from firing (here shown by XXXX on the display) to prevent unintentional injury to the friendly target.

[0069] The use of any and all examples, or exemplary language provided is intended merely to better illuminate one or more embodiments and does not pose a limitation on the scope of any claimed subject matter unless otherwise stated. No language herein should be construed as indicated any non-claimed subject matter as essential to the practice of the claimed subject matter.

[0070] The use of the terms “a”, “an”, “said”, “the”, and / or similar referents in the context of describing various embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0071] When any phrase (i.e. one or more words) appearing in a claim is followed by a drawing element number, that drawing element number is exemplary and non-limited on claim scope.

[0072] Within this document, and during prosecution of any patent application related hereto, any reference to any claimed subject matter is intended toreference the precise language of the then-pending claimed subject matter at that particular point in time only.

[0073] Every portion (e.g. title, field, background, summary, description, abstract, drawing, figure, etc.) of this document, other than the claims themselves and any provided definitions is to be regarded as illustrative in nature and not as restrictive. The scope of the subject matter protected by any claim of any patent that issues based on this document is defined and limited only by the precise language of that claim (and all legal equivalents thereof) and any provided definition of any phrase used in that claim, as informed by the context of this document.

Claims

CLAIMS1. An apparatus comprising: a) a weapon which is designed to expel a projectile by an action of a force other than combustion; and b) at the weapon, the force delivered to said projectile may be adjusted in response to a measurement of a distance between the weapon and a first object in the weapon’s line of fire.

2. The apparatus of claim 1, wherein said weapon comprises a barrel, a magazine, a trigger, and one or more of a means for storing energy.

3. The apparatus of claim 1, wherein the weapon weighs less than 100 lbs.

4. The apparatus of claim 2, wherein the weapon further comprises one or more of an information processing system and / or an information storage and retrieval system.

5. The apparatus of claim 2, wherein the measurement of distance is accomplished by a device which senses strength or frequency of signals on the electromagnetic spectrum.

6. The apparatus of claim 2, wherein the means for storing energy is a capacitor, a battery, an electric double-layer capacitor, a flow battery, a fuel cell, a flywheel, asuperconducting magnetic energy storage system (SMES), a compulsator, a spring, a reservoir of compressed gas, or a plurality of one or more of the above, or a combination of the above types of energy storage mechanisms.

7. The apparatus of claim 2, wherein the weapon may be configured to deliver one or more projectile(s) to one or more of a target(s) with a projectile kinetic energy of less than 30 Joules, and / or a velocity of less than 60 m / s upon reaching its target.

8. The apparatus of claim 2, further comprising an energy selector adapted to allow an operator of the weapon, or a remote operator of one or more of such similar weapons, to select a non-zero kinetic energy for the projectiles to possess when arriving at their respective targets.

9. The apparatus of claim 3, wherein the weapon is a coilgun or other type of electromagnetic accelerator.

10. The projectile of claim 7, wherein the projectile may comprise a metal core and / or an elastomeric or polymeric shell layer, or the projectile may comprise a plurality of metal and polymer or elastomeric portions within a single physical projectile unit.

11. The projectile of claim 7, wherein the projectile may exhibit dramatically different effects on an intended target depending on whether it strikes said target with a kinetic energy above or below a threshold value.

12. The apparatus of claim 8, further comprising an electronic display or user interface adapted to indicate the desired energy and other important information contained within the information storage system to the weapon’s operator.

13. A method comprising: a) an operator commanding a discharge a weapon system; and b) transmitting an electromagnetic, acoustic, optical, radio, microwave or other signal(s) from a subsystem of, or a device in communication with, the weapon system which is able to vary a level of energy delivered to its projectiles; and b) the weapon system receiving signals which vary in strength, frequency, or distortions; and c) at an information processing system interpreting said signals and computing a range to a target; and d) adjusting the weapon’s projectile energy based on the computed range to target; and e) the weapon firing a projectile.

14. The method of claim 13, wherein said computation of range to target occurs within 1 second of the operator’s command to discharge the weapon system.

15. The method of claim 13, wherein the transmission of signals, receiving of signals, interpreting of signals, computation, and adjustment of the weapon’s projectile energy alloccurs within or in systems electrically or optically connected to an information processing system.

16. The method of claim 13, wherein the command to discharge the weapon is in the form of the operator pulling a trigger.

17. The method of claim 13, wherein steps (b) through (e) occur within a timespan of no greater than 500 milliseconds following step (a).

18. The method of claim 13, wherein step (a) is preceded by the operator selecting between a number of different firing modes.

19. The method of claim 16, wherein step (e) is repeated a number of times until the operator releases the trigger.

20. The method of claim 16, wherein said projectiles are stored in a magazine.

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